The present invention relates to a push-button type switch that has a U-shaped guide member and one end of the guide member is movably retained in a polygonal recessed area in the button so as to lead the circuit to an open status or a close status.
Many conventional push-button type switch employs a button movably receive in a box which has two contact points are controlled to contact with each other to form a circuit close status or to separate from each other to form a circuit open status. The button must be pushed to circulate the open status and the close status. The frequent movement of the conventional button often results in break or delay response which could lead to a dangerous result. Many known push-button type switches known to applicant are disclosed in U.S. Pat. Nos. 4,167,720, 4,937,548, 5,223,813, 5,451,729, and 5,558,211. Some common shortcomings of these switch disclosed in the patents are too many parts involved in the switch and high possibilities of dysfunction happened. A flexible plate is pushed by the button frequently and the difference of temperature of the flexible plate accelerate the flexible to be broken. U.S. Pat. No. 5,223,813 discloses a switch that cannot resolve the potential problem of the flexible plate and each of the parts has a complicated shape.
The present invention intends to provide a push-button type switch that has simple structure and the button pushes or releases a movable member which is more reliable.
In accordance with one aspect of the present invention, there is provided a push-button type switch and comprising a box having a button movably inserted in an open top of the box. A tubular member extends from an underside of the button and a spring is biased between the tubular member and the box. A tongue extends from an underside of the button and a recessed area is defined in a surface of the tubular member. The recessed area has a polygonal inner periphery and a central member is located in a center of the recessed area. A first terminal plate and a second terminal plate respectively extend from a bottom of the box, and a first contact point is connected to the first terminal plate. A board extends from an inner side of the box and a hole is defined in a surface of the board. Two rods respectively extend from the inner side of the box.
A movable member has two slots and the rods are movably received in the two slots. A U-shaped guide member has a leg extending through the movable member and engaged with the recessed area. The other leg of the U-shaped guide member is inserted in the hole in the board. An oscillation member has a first end pivotally connected to the second terminal plate and a second end of the oscillation member has a second contact point connected thereto. A curved spring has an end fixedly connected to the box and the other end of the curved spring is connected to the oscillation member. The tongue contacts the curved spring.
The object of the present invention is to provide a push-button type switch that has a button having a polygonal recess to retain a guide member so as to push an oscillation member toward and contact a terminal plate.
These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.